Condenser and the method of making same



UNITED STATES? mm '1'. srArLEs, on NEW YORK, N. Y., nssienon 'ro mm-1e11mm com;

rm, mconrona'mn, on NEW YORK, N. Y., A conroimr'ro w OF-NEWYORK.

connnusna AND THE mn'rnon or magma Be it known that 1, ROBERT 'T.STAPLES, a citizen of the United States, residing at New York, in thecounty of New York. and

State of New York, have invented certain new and useful Improvements inCondensers and the Methods of Making Same/of which the following is afull, clear, concise, and exact description.

This invention relates to condensers and the method of making the 'same,the object being to provide an improved method for treatingcondensers sothat their electrical constants are quickly brought to a permanent valueand to prevent further change in such constants as a result of nor maltemperature changes.

In various telephone and telegraph circuits there is a demand'for acondenser, the capacity of which is held to very close limits and cannotchange materially without effour hours.

"fecting the operation of the circuit.

For such purposes it is a common practice to employ a condenser of thegeneral type disclosed'in Patent No. 1,200,063 of October 3, 1916, toWheelerand Sultzer. This condenser consists of alternate sheets ofconducting and insulating materials held between a pair of heavy plates,the unit preferably being impregnated in a parafline compound. Incondensers used heretofore, considerable difiiculty has been experienceddue to the change in capacity and ithas been a customary practice toplace such condensers on a shelf for a period of at least nine months inorder to allow their electrical characteristics to become constant.

In accordance with the present invention, the condenser units are placedin an oven at a temperature slightly below the melting point of theimpregnating compound, and left at this temperature for a timesuflicient to allow the units to become uniformly heated throughout. Inthe case of condensers which are impregnated with a parafiine wax, thesolidifying temperature of which is approximately 120 F., it'has beenfound satisfactory to maintain the oven at a temperature ofapproximately 110 F. and to keep the condenser units at such temperaturefor a period of approximately speciflcation of Letters l atent; j PtentdA'pulication filed au ust 17, 192o'."-serial naaoezse.

" th gh it :is theipracticein"connection with papercondensers which aresealed in a container to p'ern anize the condensers by heatlng themata-temperature inexcessof the melting point of the impregnatin --0mpoundas disclosed,- for example, '=1n nection with mica; insulated condensersruessman Patent 1,275,468: of-August 13, 1918," such a-process is notsatisfactory in .con-y which are not placed in '"a .contai'nerQWith suchunlts, 1f the impregnating wax a1 lowed to reach the melti'ngpoint,'ajcerta in amount-of this wax flows out, thus changing ,the capacity ofthe unit and alsowhen' the lmpregnating wax changes from-a solid to aliquid state or vice versa, the sudden change 1n volume causes erraticresults. {By employing .a temperature at which the impregnating wax onlybecomesplastic, all

internal stresses within the unit are allowed to dissipate andthe'unit-quickly' attains its permanent capacity value.

What is claimed is:

. 1. The method of treating afoondenser; comprising an impregnated unitwhich conslsts in heating-said impregnated unit to 'a' temperatureslightly below the melting.

point of the impregnating'compound and maintaining the unit at suchtemperature for a period of time suflicient to allow the unit to assumeits natural -shape.- 2. The method of treating "a condenser comprising aunit impregnated with a parafa fine compound having a solidifyingtemperature of approximately 120'F., which consists in heating theimpregnated unitjto for a period of not less than'th'ree hours.

' a temperature of approximately110 F. and I 3. The method of treatinga" condenser 1. comprising an impregnated unit which consists in heatingsaid impregnated unitQto a temperature at -which' the impregnatingcompound becomes plastic, but does not. be-. come fluid and maintainingthe unit at such temperature for a period of'time sufficient.-

to allow the stresses therein to-beoome dissipated.

In witness whereof, I hereunto subscribe,-

my name this 11 day .ofAug.

' ROBERT T. STAPLES.

